基于小波包能量相对熵的配电网单相接地故障区段定位  

Single-phase earth fault section location based on wavelet packet energy relative entropy in distribution network

作　　者：卢继平[1] 徐兵[2] 

机构地区：[1]输配电装备及系统安全与新技术国家重点实验室(重庆大学),重庆400030 [2]四川省电力公司眉山公司,四川眉山620010

出　　处：《电力系统保护与控制》2012年第20期26-31,37,共7页Power System Protection and Control

基　　金：国家'111'计划项目(B08036)资助;输配电装备及系统安全与新技术国家重点实验室自主研究项目(2007DA10512710101)

摘　　要：配电网发生单相接地故障时,故障点两侧暂态零序电流波形差异较大,在不同频率下的能量分布不同。结合信息熵和小波包分解,定义了具有对称性的小波包能量相对熵来识别此差异,实现故障区段定位。对馈线自动系统中沿线安装的FTU或其他测量装置获得的暂态零序电流进行小波包分解,获得其频谱能量分布特性,再计算各区段两端暂态零序电流的相对熵,比较计算结果,熵值最大的为故障区段。通过选用暂态零序电流能量最大的数据段来计算相对熵,可以避免采样不同步的影响。该区段定位方法不受过渡电阻、故障位置和故障角的影响,通过仿真分析验证了方法的有效性。The transient zero sequence current waveforms show a great discrepancy on both sides of the fault point, and have different energy distribution at different frequencies, when single-phase earth fault occurs in distribution network. Wavelet packet energy relative entropy is defined to distinguish the differences combined with the information entropy and wavelet packet decomposition, realizing fault section location. The energy spectrum distribution characteristics of the transient zero sequence currents from FTU or other measurement device in feeder automation system are obtained based on the wavelet packets decomposition. Then the relative entropy of the zero sequence currents on both ends of every section is calculated. Comparing the results, the entropy of the fault section is the maximum. The influence of non-synchronous sampling is avoided by selecting the maximum energy data segment of transient zero sequence current to calculate relative entropy. This method is immune to transition resistance, fault position, and fault angle, and its effectiveness is proved through the simulation.

关 键 词：配电网 单相接地 故障区段定位 小波包 能量相对熵 

分 类 号：TM863[电气工程—高电压与绝缘技术]